First, I do not own a roller locked anything but I would not hesitate to buy a PTR91 at the going rates. I simply would not pay $2600 for any similar type MBR. Just me, personally, but here's why;
I do not see a huge potential for increased investment value and I'm not going to retire off the resale margin of a HK anyhow. So that keeps $2600 tied up in a rifle that for me would be a user. Way I look at it is for such guns I want to use them and use them hard. For that I see no need to buy the gun you are looking at as it offers no significant performance value over and above the value and features of other guns of the type that are much cheaper. Others want that "H" "K" stamed on it and would pay for it. I wouldn't.
I did look at the roller locked guns a while back but I myself bought an ArmaLite AR10 and cannot be more pleased. It is accurate, 100% reliable, and was, comparatively, cheap. I'd do it again, too.
The roller locked guns are fascinating and really excellent "users" and I just may buy a PTR at some point, but for now, I just cannot see paying that much dough for a gun I am going quite literally to drag thru the mud.